Transesophageal Echocardiography
What is transesophageal echocardiography?
Transesophageal echocardiography is also known as TEE, or heart scan with
endoscopy. TEE uses a small probe guided into the esophagus while a child
is sedated to closely evaluate the heart and blood vessels within the
chest.
Echocardiography is a procedure used to assess the heart's function and
structures through the use of sound waves. A transducer (similar to a
microphone) sends out ultrasonic sound waves at a frequency too high to be
heard. When the transducer is placed on the chest at certain locations and
angles, the ultrasonic sound waves move through the skin and other body
tissues to the heart tissues, where the waves "echo" off of the heart
structures. The transducer picks up the reflected waves and sends them to
a computer. The computer interprets the echoes into an image of the heart
walls and valves.
Transesophageal echocardiography (TEE) uses a probe with a transducer
on the end that is guided through the throat and into the esophagus while
your child is sedated. The TEE transducer works the same as the one used
in a regular echocardiogram. However, a clearer image can be obtained,
because the sound waves do not have to pass through skin, muscle, or bone
tissue.
What are the different types of TEE echocardiography?A TEE can utilize one, or more, of four special types of
echocardiography:
- M-mode echocardiography
This is the simplest type of echocardiography, and produces an image
that is similar to a tracing rather than an actual picture of heart
structures. M-mode echo is useful for measuring heart structures, such
as the heart's pumping chambers, the size of the heart itself, and the
thickness of the heart walls.
- Doppler echocardiography
The Doppler technique is used to measure and assess the flow of blood
through the heart's chambers and valves. The amount of blood pumped out
with each beat is an indication of the heart's functioning. Also,
Doppler can detect abnormal blood flow within the heart, which can
indicate such problems as an opening between chambers of the heart, a
problem with one or more of the heart's four valves, or a problem with
the heart's walls.
- Color Doppler
Color Doppler is an enhanced form of Doppler echocardiography. With
color Doppler, different colors are used to designate the direction of
blood flow. This simplifies the interpretation of the Doppler technique.
- 2-D (2-dimensional) echocardiography
This technique is used to "see" the actual structures and motion of the
heart structures. A 2-D echo view appears cone-shaped on the monitor,
and the real-time motion of the heart's structures can be observed. This
enables the physician to see the various heart structures at work and
evaluate them.
Why is a transesophageal echocardiogram performed?TEE is used to evaluate the internal heart structures and path
of blood flow in congenital (present at birth) heart defects. TEE is also
used during heart surgery to evaluate the effects of surgical intervention
to the heart, such as repair of congenital heart defects.
When echo is indicated, but other circumstances (i.e., pulmonary
disease) that may interfere with the ability to obtain adequate images are
present, a TEE may be more appropriate. Further, certain conditions of the
heart, such as mitral valve disease, blood clots or masses inside the
heart, dissection (tear) of the lining of the aorta (the artery which
carries oxygenated blood from the heart to the body), and implanted
prosthetic (artificial) heart valves may be better visualized and assessed
with TEE than with regular echocardiograms.
Depending on the results of the TEE, additional tests or procedures may
be scheduled to gather further diagnostic information.
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